Dual-Applicator MR Imaging-Guided Microwave Ablation with Real-Time MR Thermometry: Phantom and Porcine Tissue Model...

Area of Science:

• Medical Imaging
• Interventional Radiology
• Biomedical Engineering

Background:

• Magnetic resonance (MR) imaging-guided microwave ablation (MWA) is an effective cancer treatment.
• Optimizing applicator configuration is crucial for treatment efficacy and safety.
• Real-time MR thermometry provides essential feedback during MWA procedures.

Purpose of the Study:

• To evaluate the impact of simultaneous dual applicator use on MR thermometry image quality.
• To characterize the treatment zone patterns generated by dual applicators during MR-guided MWA.
• To assess the feasibility of dual-applicator MWA for creating larger ablation zones.

Main Methods:

• MWA experiments were conducted on a 1.5-T MR scanner using commercial microwave systems.
• Phantom studies assessed the effect of dual applicators on MR image quality.
• Porcine tissue models were used with real-time MR thermometry, comparing single and dual applicators at varying distances (2.6, 3.6, 4.6 cm).
• Fiberoptic probes measured surface temperature changes.

Main Results:

• Dual applicator use reduced MR thermometry signal-to-noise ratio (SNR) to 55% (vs. 86.2% for single applicator), but image quality remained adequate for visualization.
• Temperature increases at the tissue surface were not significantly different between single (18.2°C) and dual (19.7°C) applicators.
• Dual-applicator MWA produced significantly larger treatment zones (29.4–42.6 cm²) compared to single-applicator MWA (18.6 cm²).

Conclusions:

• MR imaging-guided dual-applicator MWA effectively creates larger ablation zones.
• Adequate real-time MR thermometry image quality is maintained for monitoring treatment zone evolution.
• Dual applicator MWA offers a promising approach for enhanced thermal ablation therapies.